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Ice retreat in Wilkes Basin of East Antarctica during a warm interglacial 期刊论文
NATURE, 2020, 583 (7817) : 554-+
作者:  T. Blackburn;  G. H. Edwards;  S. Tulaczyk;  M. Scudder;  G. Piccione;  B. Hallet;  N. McLean;  J. C. Zachos;  B. Cheney;  J. T. Babbe
收藏  |  浏览/下载:19/0  |  提交时间:2020/08/09

Uranium isotopes in subglacial precipitates from the Wilkes Basin of the East Antarctic Ice Sheet reveal ice retreat during a warm Pleistocene interglacial period about 400,000 years ago.


Efforts to improve sea level forecasting on a warming planet have focused on determining the temperature, sea level and extent of polar ice sheets during Earth'  s past interglacial warm periods(1-3). About 400,000 years ago, during the interglacial period known as Marine Isotopic Stage 11 (MIS11), the global temperature was 1 to 2 degrees Celsius greater(2)and sea level was 6 to 13 metres higher(1,3). Sea level estimates in excess of about 10 metres, however, have been discounted because these require a contribution from the East Antarctic Ice Sheet(3), which has been argued to have remained stable for millions of years before and includes MIS11(4,5). Here we show how the evolution of(234)U enrichment within the subglacial waters of East Antarctica recorded the ice sheet'  s response to MIS11 warming. Within the Wilkes Basin, subglacial chemical precipitates of opal and calcite record accumulation of(234)U (the product of rock-water contact within an isolated subglacial reservoir) up to 20 times higher than that found in marine waters. The timescales of(234)U enrichment place the inception of this reservoir at MIS11. Informed by the(234)U cycling observed in the Laurentide Ice Sheet, where(234)U accumulated during periods of ice stability(6)and was flushed to global oceans in response to deglaciation(7), we interpret our East Antarctic dataset to represent ice loss within the Wilkes Basin at MIS11. The(234)U accumulation within the Wilkes Basin is also observed in the McMurdo Dry Valleys brines(8-10), indicating(11)that the brine originated beneath the adjacent East Antarctic Ice Sheet. The marine origin of brine salts(10)and bacteria(12)implies that MIS11 ice loss was coupled with marine flooding. Collectively, these data indicate that during one of the warmest Pleistocene interglacials, the ice sheet margin at the Wilkes Basin retreated to near the precipitate location, about 700 kilometres inland from the current position of the ice margin, which-assuming current ice volumes-would have contributed about 3 to 4 metres(13)to global sea levels.


  
Climate From the McMurdo Dry Valleys, Antarctica, 1986-2017: Surface Air Temperature Trends and Redefined Summer Season 期刊论文
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 2020, 125 (13)
作者:  Obryk, M. K.;  Doran, P. T.;  Fountain, A. G.;  Myers, M.;  McKay, C. P.
收藏  |  浏览/下载:6/0  |  提交时间:2020/08/18
McMurdo Dry Valleys  weather observations  summer season  
The local Last Glacial Maximum in McMurdo Sound, Antarctica: Implications for ice-sheet behavior in the Ross Sea Embayment 期刊论文
GEOLOGICAL SOCIETY OF AMERICA BULLETIN, 2020, 132 (1-2) : 31-47
作者:  Christ, Andrew J.;  Bierman, Paul R.
收藏  |  浏览/下载:6/0  |  提交时间:2020/07/02
The Representation of Fohn Events to the East of the Antarctic Peninsula in Simulations by the Antarctic Mesoscale Prediction System 期刊论文
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 2019, 124 (24) : 13663-13679
作者:  Kirchgaessner, Amelie;  King, John;  Gadian, Alan
收藏  |  浏览/下载:5/0  |  提交时间:2020/02/17
Fohn  Antarctic  AMPS  AWS  
Relationships of West Greenland supraglacial melt-lakes with local climate and regional atmospheric circulation 期刊论文
INTERNATIONAL JOURNAL OF CLIMATOLOGY, 2019
作者:  Rowley, Nathan A.;  Carleton, Andrew M.;  Fegyveresi, John
收藏  |  浏览/下载:11/0  |  提交时间:2019/11/27
Greenland blocking index  North Atlantic Oscillation  polar  supraglacial melt-lakes  
The Effect of Foehn-Induced Surface Melt on Firn Evolution Over the Northeast Antarctic Peninsula 期刊论文
GEOPHYSICAL RESEARCH LETTERS, 2019, 46 (7) : 3822-3831
作者:  Datta, Rajashree Tri;  Tedesco, Marco;  Fettweis, Xavier;  Agosta, Cecile;  Lhermitte, Stef;  Lenaerts, Jan T. M.;  Wever, Nander
收藏  |  浏览/下载:10/0  |  提交时间:2019/11/26
foehn effect  surface melt  Antarctic Peninsula  Larsen C ice shelf  firn densification  
Transit Times and Rapid Chemical Equilibrium Explain Chemostasis in Glacial Meltwater Streams in the McMurdo Dry Valleys, Antarctica 期刊论文
GEOPHYSICAL RESEARCH LETTERS, 2018, 45 (24) : 13322-13331
作者:  Wlostowski, A. N.;  Gooseff, M. N.;  McKnight, D. M.;  Lyons, W. B.
收藏  |  浏览/下载:6/0  |  提交时间:2019/04/09
chemostasis  residence time  Antarctica  hydrology  water quality  hyporheic zone  
Foehn Event Triggered by an Atmospheric River Underlies Record-Setting Temperature Along Continental Antarctica 期刊论文
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 2018, 123 (8) : 3871-3892
作者:  Bozkurt, D.;  Rondanelli, R.;  Marin, J. C.;  Garreaud, R.
收藏  |  浏览/下载:4/0  |  提交时间:2019/04/09
foehn wind  extreme high temperature  atmospheric river  climate variability  meteorology  regional climate modeling  
Near-Surface Refractory Black Carbon Observations in the Atmosphere and Snow in the McMurdo Dry Valleys, Antarctica, and Potential Impacts of Foehn Winds 期刊论文
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 2018, 123 (5) : 2877-2887
作者:  Khan, Alia L.;  McMeeking, Gavin R.;  Schwarz, Joshua P.;  Xian, Peng;  Welch, Kathleen A.;  Lyons, W. Berry;  McKnight, Diane M.
收藏  |  浏览/下载:7/0  |  提交时间:2019/04/09
refractory black carbon  snow  aerosols  Antarctica  
Decoupled responses of soil bacteria and their invertebrate consumer to warming, but not freeze-thaw cycles, in the Antarctic Dry Valleys 期刊论文
ECOLOGY LETTERS, 2017, 20 (10)
作者:  Knox, Matthew A.;  Andriuzzi, Walter S.;  Buelow, Heather N.;  Takacs-Vesbach, Cristina;  Adams, Byron J.;  Wall, Diana H.
收藏  |  浏览/下载:7/0  |  提交时间:2019/04/09
Body size distribution  climate change  McMurdo Dry Valleys  Nematode  Scottnema lindsayae  soil fauna  soil microbe  traits